If someone says they have a success rate of close to 100 percent in treating a major health problem but offer little evidence to back that up, you might be excused for being more than a tad skeptical. And a new study says you would be right.

The health problem in question is osteoarthritis (OA) of the knee, something that affects almost 10 million Americans. It’s caused by the wearing down of the protective cartilage in the knee. That cartilage acts as a kind of shock absorber, so when it’s gone you have bone rubbing against bone. That’s not just painful but also debilitating, making it hard to lead an active life.

There is a lot of research taking place – including a clinical trial that CIRM is funding – that focuses on using stem cells to create new cartilage, but so far nothing has been approved by the US Food and Drug Administration for wider use. The reason for that is simple. No approach has yet proven it is both safe and effective.

No evidence? No worries

But that doesn’t stop many clinics around the US, and around the world, from claiming they have treatments that work and charging patients a hefty sum to get them.

In a study presented at the Annual Meeting of the American Academy of Orthopaedic Surgeons, researchers contacted 317 clinics in the US that directly market stem cell therapies to consumers. They asked the clinics for information on the cost of the procedure and their success rate.

Only 65 clinics responded

Lowest price was $1,150

Highest price was $12,000,

Average price of $5,156.

Only 36 clinics responded with information about success rates.

10 claimed between 90 and 100 percent success

15 claimed 80 to 90 percent success

10 claimed 70 to 80 percent

One said just 55 percent.

None offered any evidence based on a clinical trial that supported those claims, and there was no connection between how much they charged and how successful they claimed to be.

In a news release about the study – which appears in the Journal of Knee Surgery – George Muschler, one of the lead authors, said that orthopedic surgeons have a duty to give patients the best information available about all treatment options.

“Recent systematic reviews of cellular therapies for the treatment of knee OA (over 400 papers screened) have found poor levels of evidence for the efficacy of these treatments to date. Current evidence does not justify the rapid rate of growth for these therapies.”

Nicolas Piuzzi, the other lead author on the study, says if the evidence doesn’t justify the growth in the number of clinics offering these therapies, it certainly doesn’t justify the prices they charge.

“The claim of “stem cell” therapy carries a high level of expectations for the potential benefits, but research is still many years away from providing clear evidence of effective treatment to patients. As clinicians and researchers, we have ethical, scientific, legal and regulatory concerns. Patients need to be aware of the status of research within the field. If they receive information from anyone offering a treatment claim of an 80 to 100 percent successful recovery, they should be concerned in observance of published peer-reviewed evidence.”